Sliding Mode Control for PMSM Based on a Novel Hybrid Reaching Law

In the speed control of permanent magnet synchronous motor (PMSM), the traditional exponential reaching law has the contradiction of fast response and heavy chattering. The sliding mode controller based on a novel hybrid reaching law was proposed to solve these problem. This novel reaching law adds power reaching law to the traditional exponential reaching law, it can solve the problem that the reaching speed of power law is slow when system is far away from the sliding surface and solve the problem of the chattering of exponential reaching law in the near sliding surface. The system state variables has good effect in inhibiting the chattering problem caused by the introduction of index term. Based on the novel hybrid reaching law, the sliding mode speed controller was designed, and Lyapunov stability theory was used to analyze the stability of the system. The simulation and experiment is compared with the traditional exponential reaching law speed controller. The results show that the system with this designed controller can achieve faster speed tracking, and has the advantages of high stability and strong resistance to chattering.